Method and means for control of electric energy.



H. W. LEONARD. METHOD AND MEANS FOR CONTROL OF ELECTRIC ENERGY.

APPLICATION FILED DEG. 7, 1905.

' Patented Sept. 19, 1911.

H. W. LEONARD. METHOD AND MEANS FOR CONTROL OF ELECTRIC ENERGY.

APPLICATION FILED DEC. 7, 1905] 1,003,925, Patented Sept. 19, 1911.

10 SHEETS-SHEET 2.

Kiwi memes v H. VI /LEONARD. METHOD AND MEANS FOR CONTROL OF ELEOTRIO ENERGY. APPLIOATION FILED DEG/7, 1905.

1,003,925. Patented Sept. 19, 1911.

10 SHEETS-SHEET 3.

l'vttneooeo Z 5 ameutoz 551;; Quota tag g H. W. LEONARD. METHOD AND MEANS FOR CONTROL OF ELECTRIC ENERGY.

- I APPLICATION IILBD 1730.7, 1905. 1,003,925, Patented Sept. 19, 1911.

' 1o SHEETS-SHEET 4.

H. W. LEONARD. METHOD AND MEANS FOR CONTROL OF ELECTRIC ENERGY.

APPLICATION FILED DEC. 7, 1906. gg gga Patented Sept. 19, 1911.

' 1O SHEETS-SHEET 5.

flG/Z 15 fifii I L -LL A /74* i 1 v wwwaww 8mm? 6am x 12! awe M213 H. W. LEONARD. METHOD AND MEANS FOR CONTROL 015 ELECTRIC ENERGY.

APPLICATIOZ}! FILED DEC. 7, 1905.

1,003,925. Patented Sept. 19,1911.

10 SHEETS-SHEET 8.

Z0 f awewtok H. W. LEONARD.

METHOD AND MEANS FOR CONTROL OF ELECTRIC ENERGY.

APPLICATION FILED DBO. 7, 1905.

1,003,925, Patented Sept. 19,1911.

l0 SHEETS-SHEET 7.

1| II: E" I I II l I l 1 H W. LEONARD.

METHOD AND MEANS FOR UONTROL OP ELECTRIC ENERGY.

APPLIO'ATION FILED D110. 1, 1905.

Patented Sept. 19,1911.

IOSHEETQ-SHEET 8.

wwwzooeo W w v f Elwue-niioz a, $4 451;? a t 1206mm r H. W. LEONARD. METHOD AND MEANS FOR CONTROL OF ELEGTRIG ENERGY.

APPLICATION FILED DEC. 7, 1905.

1,003,925, Patented Sept. 19,1911.

10 SHEETSSHBET 0.

awuentoz W. LEONARD. METHOD AND MEANSTOR CONTROL QF ELECTRIC ENERGY.

APPLICATION FILED DEC. 7, 1905.

1,003,925, Patented Sept. 19,1911

10 SHEETS-SHEET 10.

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HARR W'ARD"LE-orient); or BRONXVILLE, NEW rosin .3"; 5.1:

METHOD AND MEANS FOR CONTROL OF ELECTRIC ENERfiY.

Specification of Letters Patent. Patented Sept, 1:9,

Application filed December 7, 1905. Serial No. 290,683.

To all whom it may concern:

lie-it known that I, HARRY WARD LEON- ARD, a citizen of the United States, residing at Bronxville, in the county of \Vestchester '5 and State of New York, have invented oer-- t ain new and useful Improvements in Methods and Means for Control of Electric Energy, of which the following is a full,

clear, and exact specification.

My invention relates to the control electrical energy,. and an important application is the speed. control of electricmotors, although it is useful for the controlof many other forms oftran'slating devicessuch as storage batteries, electric furnaces, electric lights, transformers and other devices.

Among the objects of my;invention are the improvement of the cont rollof the elec-;

tric energy received or delivered b Such defy v$36 vices, the reduction of size, first .-cos t i I ase-e1. end.

'preciation of tlie installatio nyjit the impror ement in the.eificiencygndrelia bility of the installation. 7 t

y i The importance of. voltage control for 5 electric motors in order to vary their speed as distinguished from ohmic control is nowwel'l'understood. j

n; pfi i e' 'appilt a iq S a N 269331, filed, July 12,1905, I have described a method'and means by which a variable and reversible electromot'ive 'force is employed in connection with .a supply system so as to very materiallydecrease the cos and size f the regulating apparatus and in which the cfiiciency is considerably increased; in the form described the watt ca.- pacity of the regulating and controlling apparatus under the conditions assumed vand. with a three-wire system being one third of that of the motor.contrslled.

By my present invention I further reduce the size and .cost of the regulating and controlling devices. Thereduction in'first'cost, conversion losses, size and. weight together with other advantages obtained. make my presentmethod and system of control a very desirable. one, particularly for controlling motors'in factories,.e lectric elevators, printing establishments,- installationsbn shipboard, traveling cranes,linining installations, railway trains, storage-battery installations,

and in fact in, any. case where refinement of control, efiiciency; freedom from deprecitftion, reduced first cost, or reliability of service are-to becOns'idered important factors.

tions, such as inrailway operations where #0 the character of the supply system is; changed in passingthrough-diiferent' secti v l a L My invention has various applications not referred I to: specifically herein'andis capable $5 of being practiced in difierent waysan'd'em bodied in constructions which may.,=difier widely, from. each other. I am thereforev limited in the scope thereof only as indicated by theappended claims. I 1

My invention will be understood from the followingzdescription read in connectionwith the"accompanying drawings.

Figure 1 is a diagram of apparatus an connections for practicing my invention in one form; Fig. 2 is .a diagram of connections and development-of a drum controller 1 for carrying out the methodof operation 7 desc'ribedwith reference to Fig. 1; Fig.3 is a plan .view illustrating one form of interlocking means for the controlling and reversing switch; Fig. 4 is a diagram eating a three-Wire supply systemwith the voltages between the intermediate and outside conduotors equal; Fig; 5 is a diagram of apparatus and connections with a fourwire local system assumingcertaln values of the various voltages; Fig. 6 is a diagram for a five-wire local system with certain assumed. values of voltages; Fig. 7 is a diagram with a four-Wire supply system and certain assumed voltages; Fig. 8 is a dia gram showing a difi'crent means for deriving the different electromotive forces from I that shown in Fig. 7 and from an alternating current source; Fig, 9 shows in din-- gram an alternating current system to wh ch my invention is applied; F1g. 101s a diagram showing an alternating current source and means for deriving direct current for the multiple voltage supply mains; Fig. 11

shows in diagram a polyphase alternating current source and means for deriving direct current for the three-wire mains; Fig. 12

indicates a direct,cons'tant current sourcewith means for deriving multiple voltages for the multiple voltage mains; Fig. 13 is a diagram of a railway system to which my invention is applied; Fig. 14 indicates an alternating current source with means for conversion to direct current and for dividing .the voltage; Fig. 15 is a diagram showing my invention'applied-to a crane; Fig. 16'is a diagram of apparatus and conneetlons for remote and multiple unit control; Fig." '17 is'a diagram of a system for remote con-' trol with automatic means for controlling the action; Fig-18 is a diagram showing my invention applied to an elevator system.

with control of the apparatus from the car; and Fig. 19 1s a dlagramshowing a three; wire supply and certain different voltages assumed; Figs. 20 and, 21 are diagrams showing modifications of my invention.

Referring to Fig. 1, a main source of energy :is indicated at 1, which in the present instanceis. assumed to be a source of direct current. Between the supply mains from this source are connected two dynamo electric machines 2, 3 and from the outside tel minals and from the intermediate connection extend the three supplymain's 4, 5 and 6. The machines. 2, 3 are mechanically coupled and rotate at a constant speed operating tomaintain constant potentials onthe three supply .-mains in a manner now well understood. .Ihave' assumed that the electromotive force of machine -2--,is 100 volts and' that of machine 3 to be 200volts, thus --*I have indicated the potential of line 4 ast),

that of line 5 as 100, and that of line 6 na -300. The translating device to be controlled is shown as a motor having the armature 7 and field 8. The field 8 is con nected across ,the outside supply mains,

through a 'reversing switch 9 by which the strength and-polarity of the field may be controlled. The variable source of electromotive force is shown as a dynamo electric machine havingthe armature 10and field 11, the latter being excited by windings connected across the outside mains through the controlling and reversing rheostat 12. The armature 10 is shown as being driven in the present instance by a motor 13, and a rheostat 14 shown connected in the field strength of field 11 by circuit and solely by what may be termed voltage control. We may assume that the current capacity of the motor controlled and that of the variable source of electromotive force is the same, that the electromotive force of the armature 10 is 50 volts and that the maximum electromotive force of the an mature 7' to be controlled is 350 volts. Under these conditions the watt capacity of the regulating and controlling means 1s only one-seventh of that of the motor controlled.

The mode' of operation of Fig. l is as follows: The motor 13 may be assumed to run at a practically constant speed driving the armature 10 at constant speed in its variable and reversible field. The field 8 of Y the driven motor may be assumed to be constant, and in starting, the rheostat 12 will be in such a position thatthe field 11 has zero strength or is at a minimum strength. The terminals of the armatures 10 and 7 are designated 'for convenience by the numerals 19, 20,21 and 22. The switches 15, 16, 17, and 18 are indicated as pivoted switches adapted toengage the'clips of the contacts edgewise and to make engagement with any contacts desired without necessarily engaging intermediate contacts in passing to the new position. In starting, these switches engage contacts so that the armatures 10 and 7 are directly connected in a local loop, as in the position shown. A low voltage is thus applied to the armature 7.

and byadjusting the rheostat 12, this voltage may be gradually increased to fifty volts, which is assumed to be the maximum voltage of armature It). To increase the speed, the connections made by the armature switches are now changed so that the armatures l0 and 7 are connected in series between the niains 4 and 5. This is accomplished" by moving switch 16 so as to connect terminal 22 to main5, by moving switch 17 to connect terminal 20 to main 4 and by moving switches 15 and 18 to connect .terminals 19 and 21. With the strength of ,fieldll'jstill at its full value and in such a direction that the armature 10 generates an electromotive force counter to that of the mains 4, 5 the armature 7 will be subjected to a, resultant electromotive force of fifty volts, it being'the same value and in the same direction as when thearmature 7 was previously connected in a local loop with armature -10.' By now decreasing the means of the rheost-at 12,'-the counter volts of armature 10 will be gradually decreased and'theresultant electromotive force applied to the motor to 125' be controlled will-be gradually increased, and when the circuit of the fieldll is opened at the rheostatthe counter volts will be zero and the armature 7 will receive the voltage between the mains 4, 5. The same speed of the motor controlled will be obtained by connecting the armature 7 directly across the mains 4, 5 as by changing switch 18 to connect terminal 21 to main This is a desirable running position, as the conspeed by again connecting the armatures 10 i and 7 in series between the mains 4, 5 as above described, andby reversing the excitation of field 11 and gradually increasing its strength by the rheostat l2. The electroniotive force'generated by armature 10 will now-be in the same direction as that between mains 4, 5. The electromotive force supplied to the armature '7 may there fore be increased to 150 volts with these connections, the volts of armature 10 being added to that of the mains 4, 5. Further increase is next secured by connecting the armatures 10 and 7 in series between the mains 5, 6 the armature 10 being connected in such a direction that its electromotive force opposes that of the mains.

As the electromotive force between the mains 5, 6 is 200 volts and as the armature 10 is generating in its full field an opposing electromotive force of 50 volts, the resultant electromotive force applied to the armature Will be 150. To secure this result terminal l9'is connected by switch 15 to line 6. Terminal 22 is connected by switches 16 and 18- to terminal 21 and terminal 20 is connected by switch 17 to line 5, the field 11. remaining at its full strength as before. By gradually weakening the field 11, the counter electromotive force of armature 10 is gradually reduced to zero and the armature 7 will then receive 200 volts. The same result may be secured by connectingthe armature 7 directly between the mains 5 6 by means of switches 17, 18, connecting terminal 20 to line 5 and terminal 2l.to line 6. This cuts out of circuit the controllingdevice and is.

therefore a desirable running osition. To further increase the electromotive force applied to armature 7, the two armatures will crease again be connected in series as before between the mains 5, 6 and by reversing the field l1 and gradually increasing its strength, the electromotive force applied tov the motor will be that of the mains 5, 6

plus the voltage of armature 10, or 250 volts. Now, while maintaining the field 11 at its full strengtln'the connections of the armatures'may be changed so as to connect them in series across the mains 14-,6 and insuch direction that theelectro notive force of armaturelO opposes that-of the inains' t, 6.

This result is attained byQcohnect-ing terminal 20, to lineag'terminal 22 to line 6, and connecting terminals" 19, and 2 l to each other.- Wea1eening thefie1d 11 willlIioW clethe gounter volts f gfihat BOO'volts In some cases it will be trolled by means of the rheostat9: .Also'if' the torque is light, increased speed may be obtained by weakening the field of motor 13, by means of thefield .rheostat 14.

It will be understood that during the operation above described the motor 13 and the variable vsource of' electromotive force each operate sometimes as a motor and sometimes as a generator. It will also be seen that when the armatures 10 and 7 are connected in a local loop, a reversed electromo-tive force may be applied "to armature 7 by reversing the field 11, which will give a reversed rotation of the motor. It will also be understood that the direction of rotation of the motor controlled may be reversed under the conditions of operation above described, either by reversing its armature or field connections.

the preceding assumptions as to voltages, the same speed of the motor could be obtained by difierent connections, for example, when the. armature 7 was connected directly between the mains 4, 5 the speed was practically the same as when the armature 7 was connected in series with armature 10 between the mains 4, 5 and when the field 11 had zero strength. Also when the armatures 10 and 7 were connected in series across mains' i, 5 with the field 11 having its fuli strength and the armature 10 generating counter volts, the speed was the same substantially as when the armatures 10 and 7 were connected in a local loop and the field 11 has its full strength. I therefore in some cases prefer to make the maximum voltage of armature 10 less than '50 volts so that in passing through the successive steps an increased speed will result ineach case and the advantage is also secured that the capacity of the variable source of 'sirable running points, suclr as-the star wheel; and to otherwise improve the construction and operation. These however, form no part of my invention and as such constructions are now well understood, it is unnecessary to illustrate the detailed constructi on. r

In Fig. 2 I have diagrammatically indicated the connections to the fingers and the development of 'the drum contacts to secure the results above described with reference to Fig. 1, by means of a single controlling means. On line 28 of Fig. 2 are indicated a series of contacts representing the fixed contacts of the controlling switch and they are designated by the same reference characters as used in Fig. 1. In addition are contacts;

24, 25, 26, 27 with intervening rheostat contacts, and contact 28. These are for controlling t-he direction and strength of the field 11, and if desired an additional rheostat 29 may be used in the field circuitto secure finer gradations of electromotive. force control than is secured by the drum contacts. When the switch ismoved so that contact'of the fingers is made on line 30,the armatures.

l0 and 7 will be connected in a local loop and resistance will be inserted in the circuit of field ll so-that its strength is weak. This will give a low electromotive'force applied to the armature 7 and consequently a low' speed. Further movement of the switch will cut out resistance from the circuit of field 11 and theelectromotive force is thereby increased. At position 30 the armatures v ill-be connected in series between the mains 4,- 5 and the electromotive force of armature 10 will be counter to the lineas above described with reference to Fig. 1. By further movement, field 11 is weakened so that the electromotive force applied to,

the motor gradually approaches that between the mains 4, 5. armature 7 is connected directly across the mains 4, 5. At position 3O the armatures are connected as in position 30, but the field 11 is reversed. With these connections,

the further movement of the controlling switch will cut out resistance in the circuit of field 11, and the electromotive force 'generated by. armature 10 will be added to that across the mains 4, 5 thus increasing the electromotive force supplied to the motor controlled. At position 80 the armatu'res are connected in series across the mains 5, 6

and armature 10 is connected so that its electromotive force is counter to thatof the At position 30 the 30 the motor armatures are connected in series across the mains 4, 6 and the electromotive force generated by armature 10 is counter to that of. the supply mains. Further movement of the switch will insert resistance in the circuit of field 11 which will decrease the counter volts. At position 30 the armature 7 is connected directly across the mains 4, 6. At positionBO, the armature connections are the same as at position 30 but the field 11 is reversed, and as the reslstance in the circuit is gradually cut out, the electromotive force applied to the armature 7 will be'boosted to the electromotive force. between the mains 4, 6 plus'the full el ectromotive force of armature 10.- It is therefore apparent that -with this controlling switch the samesequence of connections is made and the mode of operation carried out as above described with reference to Fig. 1.- It is obvious that the contacts of this switch. may .be arranged in various ways to secure the sequence of connections above described. If it is desired to reverse the rotation of the motor, the controlling switch will be moved fromofi position so that the fingers make contact on line 30. In thisposition t-hearmatureS-IO'and 7 are connected on a local loop but the field of armature 10 is reversed with reference to its. condition at position 30. A reversed electromotive force is therefore applied to armature 7 and when the controlling switch is moved to cut out the field resistance, the reversed electromotive force is increased to. the full electromotive force of armature 10. In many cases this comparatively slow reverse movement will be all that is desired. When it is desired to control the motor to its full speed in a reverse direction, the reversing switch 31 in the circuit f armature 7 may be thrown and the controlling switch willthen be turned as above described, giving the same graduations of speed in the reverse direction. It is preferable to interlock the reversing switch, such as the switch .9 in the circuit of the field 8, if the latter reversing switch is used, with the main controlling switch.

In Fig. 3 I have indicated one form of interlocking device. The operating handle of the main controlling switch is indicated at 32, and the operating handle of the reversing switch in the field or armature circuit of theimotor controlled is indicated at 33. On the shaft of the main controlling switch is fixed a plate 34 having a recess in which one end of the pin or plunger 35 may' seat." The shaft of the reversing switch, which is assumed to be ofthe' drum type, carries a plate 36 having recesses 37 against which the in 35 is normally pressed by a spring 38. hen the reversing switch is in the open circuit position such as .indicated, thep'in 35 is pushed by the plate 36 and seats in therecess of the plate 34 thus locking the latter. In operation the reversing switch must firstbe thrown to one or the other closed circuit positions. The

pin is then forced into one ot the recesses 37 by the spring 38 and the main'switch may then be moved. If it is desired to reverse the direction of rotation of the motor, the main switch must be turned to its off position before the reversing switch can be changed. In the olf position of the main switch, the recess in the plate 34 is opposite the pin 35 which will permit thevlatter to be moved. into this recess when the reversing switch is operated, otherwise the pin 35 is prevented, from movement by the edge of the plate 34. Although I have described a form of mechanical interlock, an electrical interlock could be used in its place.

' reversed.

It may be desired in some instances to obtain forward and reverse operation of the motor controlled to the maximum speed in each direction by operating a single con-,

trolling handle or lever. In such a case a controller could beused of the type described with reference to Fig. '2 with the addition'of another set of contacts on thedrum, and in which additional set of contacts the connections of the contacts engaged by the terminals of armature would be My invention is applicable to many forms of supply systems, and in Fig. 4 I have indicated the usual three-wire system in which the voltage between the neutral and each of the outside wires is the same and is indicated as .100 volts in the figure. The maximum electromotive force of the 4 variable source of electromotive force required in this case would be 50 volts, and the mode of operation would be similar to that already describedexcept that less range of speed is obtained.

In Fig. 5, there is indicated the common three-wire system assumed to have a difference of 100 volts between the neutral and each 'of the outside wires. In addition thereto is shown a motor generator 39 which I as follows 50 150' and 250. A battery 41 is con nected between the mains 4 and 40 to assist the motor generator 39 to maintain the potential diiference of 50 volts and thus permit the capacity of the motor generatta to be I reduced. With this arrangement the maximum electromotive force of the variable source need notexceed- 25 volts. The mode of operation of the apparatus shown in Fig. 5 is similar in general to that described with reference to Fig. 1,.and with reference to the particular form shown in Fig. 5 the operation may be briefly described lVith the field 11 at zero strength, the switches 15, 16, 17-, 18 are moved so the armatures 10 and 7 are closed upon a local loop. The field 11 is then increased, giving 25 volts'upon the armature 7. Armatures 10 and 7 are then connected in series across the mains 40 and 4 with the elect-romotive force of armature 10 counter to that of the mains 40, 4, after which the field 11 is gradually reduced; Direct con nection of. armature 7 may then be made across the mains 40, 4. With the same former series connection of the armatures between mains 40, 4 the field 11 will be built up inthe reverse direction. .The motor armatures are then connected across. the mains 4, 5 with the full voltage .of the armature 10 counter to that of the mains 4, 5, after which the strength of field- 11 is reduced and direct connection of the armature 7 may be made across the mains 4, 5. The same series connectionof. the armatures may then again be made between mains 4, 5 and the field 11 built up in the reverse di rection giving'a total of 125 volts applied to armature 7. The next connection isa series connection of the motors between the mains 40, 5 with the armature 10 counter to the line electromotive force, and by weakening the field strength of the armature 10,. the electromotivc force applied to armature 7 maybe made that between the mains 40, 5, or ]50'volts. Direct connection of the armamade.

the armature of the motor will be increased to 175 volts. The motor armatures will next be connected in series across the mains 4, 6 with the armature 10 such that it opposes the line-electromotive force, and by decreasing its field strength the volts applied to the motor armature will approach By again making the same series connection of the armatureslbetween the mains 40, 5 and by. reversing and increasingthe strength of field 11, the volts applied to l 200. This same voltage will be applied to the motor armature by direct connectionof. its. terminalsto the mains 4, 6. lVith the same series connection of the motor armatures acrossthe mains 4, 6 and by reversing and. gradually building up the field 11, the voltage applied to the motor will be inalso beobtained by direct connection of the 7 source of supply is a 240 volt source.

will be noted that the high voltage difi'er ence of 120 volts is between the two interprevously described and afterconnecting creased to 225 volts. The armatures may then. be connected in series between the mains 4:0, 6 with the electromctive force of armature 10 Opposing that of the line. Decreasing the strength "of field 11 will increase the voltage applied to the motor to 250 volts, and this voltage on the motor may armature 7 across the mains 40, 6. The condition for maximum speed 'can now ,be reached by making the same series connection of the armatures across the mains l0, 6 and by reversing and gradually'increasing the strength of field 11, giving a final voltage of 27 5.

In F ig. 6 there is indicated a distant source supplying energy to three-wire mains with a potential diiterence of 100 volts be-' tween the neutral. and each of the outside conductors. There is also indicated a fivewire supply system derived from this source by means of a set of'balancers 42 mounted on the same shaft and serving to maintain constant potentials on the intermediate eonductors 43, 44. In this instance I have 515- vice 56, which may be an alternating current motor, 1s-connected to the switches 17, 18.

sumed that the potentials'maintained on the difi'erent supply mains 4, 43, 5, 44 and 6 is 0', 33, .100, 133' and 200'. Withthis system the maximumelectromotive force of the variable source need not exceed 16% volts. The operation of the apparatus .of this figure, to secure a gradual change of electromotive force from zero to 216%., is similar in general to the method already'described,

and, it need only be stated that the procedure of' operation is to pass from the local loop to a connection between reiimains i, 43, then to connections betwee e mains 4-3, 5, thenbetween. mains 45, 5, 1 4:, 4:4, then mains 43, 6 d finallymains 4, 6. It will be r derstgod'that the intermediate ste's'and changesffoi connections corresponlin generalwith ose previously described.i 1' J In Fig. 7 that, s shown nected between the'joutsiid e 6, and intermediate er'nhflilcto from the battery from such points as to give potentials corresponding to O", 40, 160, and

240 as indicated, it being assumed thatthe mediate conductors. With this system the variable source may generate 20 volts and the mode of operation is similar to that the motors in the localloop they-will be connected between mains 4, 46, then between mains 4:7", 6, then between mains 46-, e7, then mains 4, 47, then mains a6, 6, and 'finally mains 1 between mains I plymains i,

In Fig. 8 I have indicated an alternating current source of cnerg' 48 which may be single phase or polyphase and which is .illusl 'trated as single phase. I have also indi-, 'catcd a divided source of direct current energy derived therefrom by means of a motor generator 4!) on the shaft of which are also fixed the revolving elements 50, 51- of dynamo electric machines which will main tain the desired potentials upon the mains 4, 46, 47, and 6, and. which are designated as represented by 0, 40, 160, and 240, Ire-l spectively, as in Fig. 7. v In Fig. 9n1y invent on is shown apphe to a system in which alternating current-is employed throughout. The original source: is indicated at 48, supplying current to the static transformer 52, from: the secondary;

winding of which extend four supply mains 53; The variable and reverslble source of electromotive force may be any. desired 'form of alternating current voltage controller and is indicated in this case as being of the induction type having the stationary part 54 and its windmg connected across the outside 'supplymains and also having a movable part 55. with its winding connected to the switches 15, '16. The tr anslating de- The mode of, operation is similar in general to that above described, passing from the local loop connection to various" connections between the supply mains and with the variable source sometimes acting with the electromotive force of the supply mains and sometimes counter thereto.

In Big. 10 is indicated an alternating current high tension source 48, supplying energy to a static transformer 52 which lowers the elect-romotive force. Fromthe transformer 52 connection is made to'the rotary convert-er 57. A battery 58 is connected acts to sub-divide the derived direct current electromotive force and maintain fixed potentials on the various supply mains, four being indicated in this figure.

between the mains from, the rotary 57 and In F ig ll-is indicated a polyphase source or energy and a,motor generator supplie'tl'; witli energy,therefrom. The motor generator comprisesan. alternatingcurrent motor 60 and a generator 61 which delivers 'direct .cur'rent energy to the mains and I have indicated this generator as being of.

the type which the outside mains are con-v n'ected to the commutator and the i'ieiilral is maintained at an intermediate potential. by any known method, for example by some special device, such asin the patent to U01)- rowolsky, No. .513006.

ring 62 adjacent to the connnutalor.

\' In Fig. 12 is indicated a source 33 of con- The intermediate conductmof the ;mult11')le yoltage mains .thereiore"shoWn connected to a collector )racticin 1n invention. a

In Fig. 13 I have indicated a source 66 of high tension alternating current energy whlch 1s supplled to the malns 67 of a rallway system. Upon the vehicle 68 is inclicated a static transformer 69 to reduce the lngh tension current taken from the line through moving contacts, and from the transformer 69, energy is transmitted to a rotary converter 70 receiving the alternating current at one end and giving direct current from the commutator to the outside supply mains. The intermediate conductor of the three-wire supply mains is connected to the collector ring 62, it being assumed that the converter is provided with some auxiliary means for maintaining the constant potential of the intermediate conductor. The controlling devices for controlling the driving motor or motors of the vehicle are indicated as being connected to the lhrecavire supply mains, and a drum controller is indicated at 71 which controller will form the sequence of connections and carry out the mode of operation as above described, such for example as with reference to Fig. 2.

In Fig. 14 is indicated a different means that mi ght'be employed for deriving divided direct current energy from an alternatingcurrent source. The source 66 of alternating current supplies energy to a rectifier 72 of approved type from which mains extend to the battery 58. From this battery extend the supply mains of diflerent potential.

My invention will be of value in the operation of cranes. Such an application is indicated in Fig. 15, in which asource of direct current is indicated at 1, and from the supply mains 73, current is led to the crane indicated at 74. I have shown as mountedupon the crane a balancer set composed of three dynamo electric machines. 7 5 from which extend four multiple voltage mains. In the operation ofa crane of this type, three motors are usually employed, one for moving the crane as a whole, another for movin a traveling part {cross-wise, and the third or hoisting and lowering. In the figure I have indicated three regulating and driving sets 76, each operated from the four multiple voltage conductors, and .for each of these sets is indicated a controller 71.

. By means of these three controllers, each of the driving motors may be controlled in accordance with my invention and as already described.

Instead of controllingthe apparatus di rectly by hand control, I may introduce in termediate automatic means, and also secure control from a distant point. Such an arrangement is necessary where the operator is at a considerable distance from the apparatus, for example, when my invention is applied to. the operation of elevators. It is also important in many cases to simultaneously control a plurality of motors by means of a single controlling device and to control the same motor from a number of points, such as in the operation of trains. Fig. 16 illustrates diagrammatically apparatus by which these'requirements are fulfilled. In this figure the parts similarly numbered correspond to the same parts in previous figures. In the present figure the leads from the armatures 7, 10 are connected to contacts of automatic switches 77 78, '79, and 80. These switches are closed by the action of coils 81,'which when excited, raise their cores and close the switches. The connections of switches 77 to 80 are such that when any one is closed a desired relation of the armatures 7, 10 to each other and to the mains 1, 5, 6 is secured. In the figure are shown a set of contacts on line 82 and the development 01 contacts on the drum of a controlling switch, which contacts are adapted to be engaged by those on line 82 when the controlling drum is operated. This controlling switch may be located at any desired different point, and is adapted to control the circuits of the coils S1 and also the direction and strength of the field 11 of the variable source of electromotive force and of the fieldS of the motor con trolled. The contacts on line 82 beginning at the top and going down are connected as follows: Contact 83 is connected to main 4:, contact 83 is connected to one-terminal of each of the coils 81, contact 83 is connected to the remaining terminal of coil 81 of the of coil 81 of the switch 80, the next two contacts 83 are connected to the main 6, contact 83 is connectedto a terminal of the circuit of field 11 and then follow a set of field resistance contacts, contact 83 is connected to the other terminal of the circuit of field 11, the next two contacts 83 controlling devices and contacts 83 are connccted as through conductors, so that any number of controlling devices may be con nected to the conductors84 and operated simultaneously by means of the single controlling switch just described. Also any number of controlling switches may be connected to the through mains 8e and control the devices from other points of control as desired. I have therefore indicated the mains 85,-which are adapted to'be'connected to anothen pontrolling switch and I have also indicated the mains 86, 87. which are adapted to connected to another set of delvi'cesand to the mains 4, 5, 6, these mains corresponding to themains 85, 86' and 87' .rotation 'of the motor controlled by move ment in one direction, and to secure reversed rotation of the motor controlled by movement of the controlling switch in the opposite direction, and also to secure full speed of the motor in each direction.- For forward operation it may be assumed that the controlling switch is moved from off position so that the contacts on line 82 engage the drum contacts on line 88 connection is then made from main 4 to the coil of switch '77 and thence through the controlling switch to the main 6. This causes'the automatic switch 7 7 to be closed, by which the armatures 10 and 7 are connected in a local loop. At the same time the circuit of field 11 is closed across 7 the mains 4, 6 with resistance in its circuit.

This causes the armature 10 to generate a low electromotive force which is supplied to the armature .7. The field of the armature 7 is' fully excited .by movement of the controlling switch at this time, being connected across the mains 4:, Q) and without resistance inits field-circuit. Movement of the con: trolling switch will cause the resistance in the'circuit of field 11 to be gradually cut out and thus increase the electromotive ,force su plied by armature 10 to the armature 7. W on contact is made on line 88*, the field connection will be unchanged but the coil of switch 77 will be deenergized and the coil of switch 78-will be energized] Switch 77 will therefore be opened, and switch 78'will be closed. 1 The closing. of this switch-causes the armatures 10 and 7 to be connected in series across the mains 4, 5. sothat the elecsistance:inFitscireuit. This causes the electhat the armature 10 will generate a low 'tromotive force of armature 10 opposesthat of the-mains 4, 5 as above described. F urthermov'ement of the controlling switch will weaken 'the field 11 by the insertion of retromotive .force applied to armature 7 to approachfthat between, the mains 4,, 5. \Vhencontact is made on line 88, the connections of=the circuit of field 11 are changed reversedelectromotive force, so that the re st lt-ant electromotive force applied to. armae-7 will-beequal to that between the;

mains 4,5 plus tha generated by armature Z' i 5' LOOSQQB opened and the coil of switch '79 is closed which will cause the switch, 79 to be closed automatically. The connections of the contacts of switch 79 are such that the armatures l0 and 7 will be connected in series across the mains 5, 6, and the electromotive force of armature 10 will oppose that of the mains. Movement of the controlling switch will now insert resistance and weaken field l1, and as the counter volts of. armature lO gradually decrease, the electromotive force applied to armature 7 will gradually approach that between mains 5, 6. At position 88 the field 11 is reversed causing the armature 10 to generate electromotive force .in the same direction as that of themains 5, 6, and as the switch is moved more this additive electromotive force is gradually in-- creased. At position 88 the coil ofswitch 79 is deenergized and the coil of switch '80 is closed, causing the closing of the automatic switch 80; The switch 80 will cause the armatures 10 and 7 to be connected in series across the mains 4:, 6, so that the electromotive force of armature 10 is counter to that of the mains. Further movement of the controlling switch willinsert resistance in the circuit of field 11 andcause the counter volts of armature 10 to be gradiuzlly decreased. At position 88 the field 11 is reversed which will cause the ar 'inature 10'to act with the line electromotive force, and when the switch is. moved farther the volts applied to the motor control-led will be gradually increased to the voltage of the outside mains plus the full voltage of the armature 10. Further movement will cause the field S of the motor controlled to be weakened by inserting resistance gradually in the field cireuit, giving full speed forward. WVhen the controller is turned back to the OE position the same connections will of course be made in the reverse order. When the controller is moved from off position so that the contacts are on line 88 reverse rotation of the motor controlled will result owing to the field connections of the. motor being reversed at the controlling switch. The connections made in this position 88 are otherwise the same as those made, in position 88 ,the armatures 10, 7 being connected inalocal loo by the switch 77. Continued movement 0 the controlling switch .in the reverse direction wi l secure the samesequence of connections as described with reference to the movement of to 88 the only difference being. that the field circuit of the motor controlled is reversed. Th1 s a single controlling switch secures for war; and reverse rotation of the driven inc-- toe to full speed in each direction. Also with a switch of this typejthecurrents flowing throughthe same are very small and the size of conducting wires and other parts is ve y greatly reduced so that only a comparatively small controlling switch is required. It is evident that this switch may be any desired distance from the apparatus controlled, that it will control similar apparatus whichinay be connected to the mains 84, and that other similar switches may be connected to the mains at other points and control the same apparatus. i

In some cases-it will be desired to have the action of {he switches entirely automatic so, that when a circuit .is closed a switch the sets of solenoid switches will be operated automatically to bring the motor co'ntro l led gradually to its full speed, and also to bring the motor gradually to rest automatically when another circuit is closed or the circuit first referred to opened; "The automatic action of the switches in such cases will preferably he made to depend upon the counter elect romotive force of the motor controlled, and in carrying this into effect the invention described in my ending application Serial No "H3339 filed ecember 1'2, 190% may be .7 of operating the controlling of Fig. 16 by hand, it will sometizrhs be desirable to operate this by asmall pilotmotor, w ich pilot motor may be controlled in either direction simply throwing a double throw switch to one closed position or the other. Such an arrangement is shown in Fig. 17' in which the controlling switch of Fig. 18 with the wires leading thereto is shown at 89. This has a gear mounted on its shaft and in engagement with the gear is indicated a worm drlven by the armature 90 of the pilot motor. The field 91 of this "pilot motor has its circuit 7 connected to 'give constant strength under normal conditions, although its strength may be adjusted by a rheost'tt in its circuit to;

give a desired strength. A circuit to the armature 90 which extends from some constant, potential source, includes a double throw reversing switch 92 and an adjustable resistance to determine the .eur'rent'flow. The switch|92 will causethe 'motor controlling the switch 89, to operate in one direction when 'clos'ed one way and in the reverse direction whenclosed the other way so that any desired position of the sw1tch'89 can be secured and .thusoperate the driven motor at any speed or inv any direction desired. If desired the switch 92 for the pilot motor may be made a regulating switch having resistances to control the speed of the pilot motor. I prefer to insert some protecel'ev'ator. .ling devices are similar to. those shown 'n F 1,9,. 2 and-it as assumed that the drum. con-" tive means in the circuit of the pilot motor so that if the driven motor is'subjected toa too rapid variation on electroi'notive force, the pilot motor will be automaticall stopped and prevent any further change 0 the con-:-

trolling switch- 89 until normalconditions are restored.- This result is accompl'shed the insertion of a switch 93 in the armature circuit of the pilot motor whichswitch. is aupilot motor. When the current in the armature circuit of the driven motor decreases to a normal amount, the core 94 will be moved downward and'permit the switch 93 -toclose a ii'd the pilot moto1' may thencontinue to operate.

In Fig. 18 I have illustrated an applica tion of my invention to the'co'ntrol of-hn The supply system and control-,

trolling switeh"'71 is like that shown in Fig'g' 2. In the present figure the armature 7 is shown'as driving the drum 96 which controls the movement of the car 97 through suitable cables and guide wheels. The controlling switch 71 is shown as driven by a pilot mo. tor, the armature 90 of which is controlled by switches in the car. The circuit of the armature 7 of the driving motor is also controlled from the car soles to determine the direct-ion of current flow through the airmail ture 7 and thus its direction of rotation. I1i" the car are shown two similar switches, 93%,"

98' adapted to be thrown by hand. These switches directly control the circuit of the armature 90 of the pilot motor, causing the current from the source to pass through the armature .90 in one direction or the other. If either of the switches 98, 98 is thrown upward, current will pass through the armature 90 in one direction and rotation of the pilot motor inone' direction will result, turning the controlling switch 71 in such a direction as to cause the driven motor to op-' ei'atefat say increased speeds. If either of the" switches 98, 98' are moved downward, current will flow through the armature 90 in the reverse directionand cause the con-' trolling switch 7 1 to'be moved so as to give decreased speeds of the driven motor. There a third reversing switch 99 which con trolled by each of the switches 98, 98. The switch 99 controls the direction of currents in the circuit of armature 7. The switches 98, 98 each carry a plate having a recess 100,

and the ends of a pin lOl-are adapted to,

seat in these recesses. The pin 101 is connected to and throws the pivoted arm of the switch 99, causing itto engage one or the other pair of contacts. If it be assumed that the switch 98 is thrown upward the pin 101 is forced into the recess of the switch 98. This will lock the latter switch in position and it cannot be 'moved until the switch 98 is returned to open position. The throwing of the pin 101 causes the connections of the armature 7 to besuch that rotation thereof in one direction is secured. The switch 98, when thrown upward as assumed, causes the pilot motor to rotate in such a position as to drive the controlling switch so that an increase in speed of the driven motor is secured. If it is desired to decrease the speed of-the driven motor the switch 98 is thrown downward whichrevcrses the pilot motor causing the controlling switch to be moved backward toward its off position. When it is desired to reverse the direction of rotation of the driven motor, the switch 98 is opened after the car or'driven motor has come to a stop and the switch 98 is then thrown upward. This causes the switch 99 to be thrown so as to reverse the direction of current through armature 7 and also causes the pilot motor to rotate in such a direction as to move the main controlling switch to give increased speeds of the driven motor. Downward movement of switch 98 will reverse the rotation of the pilot motor and therefore cause the speed of the driven motor and consequently of the car to be gradually decreased.

Although I have shown the connection of switch 99 such that the current through armature 7 is reversed by its movement, it

will he understood that the field circuit 8 could be reversed by this switch if desired instead of the armature circuit.

Although my invention is specially well adapted for the control of the speed of a. motor without the insertion of resistances in the armature circuit, the conditions may be such in some cases as to make the use of such resistances advantageous, for example where there would otherwise be a considerahle jump in voltage. p

In Fig. 19 are shown supply mains 4, 5, 6, the potentials of which are assumedto be 0', 10.0 and 400: .The electromotive force of armature 10 at its maximum may be 50 volts and by carrying out the method described with reference to Fig. '1, agradual increase of voltage maybe obtained from the minimum, up to 150 volts when the armatures 10, 7 will be connected in series across themains .4, 5 and the electromotive force of armature 10 will be added to that of the mains. But in thenext step vwhen the armatures are connected in series across the mains 5, 6, with the counter volts of armature 1.0 opposing that between the mains 5, 6 there would be a jump to 25Q volts. .In thiscas'e it would be desirable to first insert a resistance in series with the armatures which would be gradually cut out or entirely out out before the counter volts of the armature 10 were reduced. I have therefore indicated a set of resistance contacts 102 for the switch 1 8 so that when the armatures are connected across the mains 5, 6 a resistance will. be included and I and 7 are connected in series across the sup ply mains, there will be three electromotive forces in the c rcuit in various relatlons.

Instead of using a dynamo electric ma chine for securing the variable and reversible electromotive force other types of apparatus may be used, for example, circuit interrupters adapted to vary the voltage. Also other means for maintaining the required potentials on the multiple voltage may be used.

Fig. 20 indicates a railway system in which thereis a single phase source of sup ply at 66, to which the conductors 67 are connected. The high tension current is led upon the car 68 and the voltage is reduced on the car by means of a static transformer 103. In order to maintain therequired po tentials upon the multiple voltage mains, rotary converters may be used as has prevl- 'ously been referred to. In the present figure I have indicated rectifier-s for transforming the alternating current, and for producing. the electromotive forces mains tained on the four multiple voltage mains which are designated as 4, 46, -17, and 6, and are indicated as having potentials 01, 40,

160 and 240. These potentials correspond to those indicated in Figs. 7 and 8, and are in a desirable ratio to each other, but of course any other desired potentials may be adopted.

There are -various different forms ofrectifiers adapted for usein connection with my invention. One form is diagrammatically indicated in Fig. 21. This consists of a laminated iron core 104 ,and has two opposite qu'arters wound with turns 105, as in :the Gramme ring winding, the coils being connected to. segments '106. Between the mains other than those already described two sets of segments 106 are located two large segments 107 each of which occupy a quarter of the circumference, and which are also connected to the turns 105 as shown. Upon the commutator made up of the seg- 

